1. Field of the Invention
The present invention relates to a heat exchange unit having a first heat exchanger serving as an air heat source, and a second heat exchanger for heating refrigerant with heated fluid, an air conditioner having the heat exchange unit, and an air conditioning system having the air conditioner.
2. Description of Related Art
In such a cold region as Hokkaido, a so-called "heat pump type air conditioner" using an air heat source in heating operation does not provide a sufficient heating effect in some cases. In order to take a countermeasure to these cases, there has been proposed a heat pump type air conditioner which is equipped with an apparatus for heating refrigerant with a boiler or the like to use the heated refrigerant as a heat source (as disclosed in Japanese Utility Model Publication No. Hei-6-33296).
In such an air conditioner, when refrigerant is directly heated by a boiler, the combustion power of the boiler must be adjusted in accordance with an air conditioning load, and thus a boiler having a capability of adjusting the combustion power or a control equipment for controlling the combustion power of a boiler must be installed into the heat pump type air conditioner. Accordingly, cost-up is unavoidable in this type air conditioner. Furthermore, in this type air conditioner , a compressor, an air blower (fan), a heat exchanger, etc. are accommodated in a housing of a heat exchange unit, and the housing is designed to have an exclusively-used space (chamber) for accommodating a heat exchanger which is used to perform heat exchange between the refrigerant and the boiler. Therefore, the housing of the heat exchange unit must be designed in large size.